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Odd (and non-functional) #RX behavior #v5 #rx


Evan Hand
 

Tim,
Did you verify that you have the correct KD8CEC code?  If so, then you can enter the BFO value in the USB Calibration field of the Memory Manager and then write the values to the ubitx Nano.



Above is a screenshot of one of my early v5 calibration settings.  All of my ubitx are in surgery, so I cannot get a clean capture of current values.

NOTES:
1 - Need to read and write the values from the ubitx each time.
2 - The values are not used until you reboot the ubitx Nano.  This includes removing the power from the USB cable.
      (be sure to disconnect by pressing the changed connect button before removing the USB cable, otherwise, you will need to close and restart the Memory Manager program)
3 - It is best to save values between trials to a file, renaming the file save location each time (i.e. Trial1, Trial2, ...)
4 - Since this capture, I found out that you only need to enter the USB Calibration, the LSB is not used and should be 0

The zero beat for frequency calibration is to be done against an AM station that you can receive and know the frequency.  Most in the US can get one of the WWV frequencies, 5 MHz, 10 MHz, 15 MHZ, or 20 MHz.
The BFO setting is through the "noise" on a frequency without a signal. You do need to connect to an antenna for this test, AND you need a microphone connected to your PC and use the Chrome browser for the BFO Tuning Aid to work.  What you see in the video from Ashhar Farhan is the noise "plateau" from a clear frequency.

WWV info:
https://www.nist.gov/system/files/documents/calibrations/sp432-02.pdf

If you cannot receive any of the WWV frequencies, then you can also us an AM station, as long as you know the exact frequency, and you take the time to tune down to the frequency on the dial (There is a shortcut direct entry on one of the KD8CEC screens).

Hope this helps
73
Evan
AC9TU


Tim Helming
 

Thanks, Evan

For the calibration, my rig does not pick up the "birdie" tones at the frequencies shown (the video has one on 40m and there's another that I've seen reference to on 20m). I can't use the calibration aide to center the tone since there isn't one.

For BFO tuning, my BFO is so far away from 11.055.500 that it would literally take hours and hours of spinning the dial to get to it. And yet, as I mentioned in an earlier post, either I'm entering the 11055000 in the wrong field in the Memory Manager, or my rig is acting odd.


Evan Hand
 

Tim,
I meant to include the v6 video by Ashhar Farhan for calibration.  The same steps and the BFO tool can be used, the controls and how to bet to the BFO calibration is different (as you will see since you have already set the BFO).  You will need to use the "yellow box" setup menu that you get when you press the encoder.

Calibration of v6:
https://www.youtube.com/watch?v=t6LGXhS4_O8

BFO Tuning Aid:
https://www.hfsignals.com/index.php/bfo-tuning-aid/

73
Evan
AC9TU


Evan Hand
 

Tim,
I believe that you have the wrong KD8CEC version loaded on your v5 ubitx.  That is why it is not working.  In the KD8CEC software, there is a boundary check that keeps you from setting the USB Calibration (BFO) to a value outside of a reasonable range (do not remember the exact value).  The version of ubitx prior to v5 had a 12 MHz crystal SSB filter, the v5, and v6 have 11.059 MHz filters.  The BFO then needs to be 2,700 Hz lower than the nominal SSB crystal frequency, with adjustments for minor crystal variations.

Go to this GitHub page: 
https://github.com/phdlee/ubitx/releases/tag/v1.20 
and be sure to get the version uBITXV5 and load that sketch into your Nano.   Then set the USB Calibration to the 11055500 value and perform the BFO rough calibration.  Verify the calibration using the zero beat method against a known short wave station, then do a final BFO calibration.  The steps for the v6 are similar to the v5 with the KD8CEC software.  The stock v5 software put the rig into transmit mode at 10.000000 MHz for the calibration step into a dummy load. 

The Master Calibration value is to set the displayed frequency to the correct value.  Since you have adjusted this, you will need to recalibrate the ubitx once you can receive a signal like WWV.

Hopefully this will fix your issues.
73
Evan
AC9TU


Tony Vandenborn
 

Hello Tim

Are you shure you really wrote the USB frequency into the Raduino board ?
You have to connect the radio to the PC ('Open'); then 'Read from uBITX', followed by 'Decode'. Now you can see what value is exactly stored in the radio.
Now fill in the desired frequency in 'USB Calibration'. Then 'Encode', and 'Write to uBITX'. Finally you have to close the connection with the radio.
As long as the Memory Manager is connected to the radio, it more or less works. I don't know if it is really necessary, but I always power off the radio from its owen supply before connecting the USB connector to the pc...

Hope this helps !

Tony ON6NT

Op wo 3 jun. 2020 om 05:29 schreef <wt1im@...>:

Please advise as to which exact setting in the memory manager needs to be on 11055500. USB Calibration is the only one that is close to that figure, but if I set it to that in Memory Manager, the BFO setting on board the radio does not show that figure. 


Tim Helming
 

Please advise as to which exact setting in the memory manager needs to be on 11055500. USB Calibration is the only one that is close to that figure, but if I set it to that in Memory Manager, the BFO setting on board the radio does not show that figure. 


 

uBitx v5 needs 11.0555 MHz BFO and if it is 11.9965 then it wont work. Put back the original firmware and see.

The microphonics is usually caused by ceramic capacitors. These are those darker brown (milk chocolate) colored
SMD parts. tap each one gently till you locate it and replace.

Raj

At 03/06/2020, you wrote:
Thank you Reed and Evan

Well, I've done some experimenting and haven't really gotten anywhere but have at least got some data.

I used the ubitx Memory Manager to program the rig. However, there's not a setting in the memory manager that corresponds directly to "the BFO value." There is a setting for Master Calibration. I found elsewhere on this forum that a value of 143000 was recommended (I read something like 124500 off the bitx). Then there are LSB (0) and USB (11996200) Calibration values.

The "BFO" menu item on the ubitx LCD shows the 11996200 value.

I tried changing that value (USB Calibration) to 11055500. However, this corresponded to 11997000 on the ubitx lcd.

Is there some different setting in the Memory Manager that I need to be overwriting?

As for the "microphone" effect, Evan, your mention of the LM386 caused me to notice that the effect does seem to be strongest near that component--tapping on or near the amp causes a much louder response than tapping elsewhere on the radio.

I looked at all the solder joints, both my own and the ones the board came with, and I couldn't find any that looked suspect.

Thanks for the assist!

Tim


Tim Helming
 

Thank you Reed and Evan

Well, I've done some experimenting and haven't really gotten anywhere but have at least got some data.

I used the ubitx Memory Manager to program the rig. However, there's not a setting in the memory manager that corresponds directly to "the BFO value." There is a setting for Master Calibration. I found elsewhere on this forum that a value of 143000 was recommended (I read something like 124500 off the bitx). Then there are LSB (0) and USB (11996200) Calibration values.

The "BFO" menu item on the ubitx LCD shows the 11996200 value.

I tried changing that value (USB Calibration) to 11055500. However, this corresponded to 11997000 on the ubitx lcd.

Is there some different setting in the Memory Manager that I need to be overwriting?

As for the "microphone" effect, Evan, your mention of the LM386 caused me to notice that the effect does seem to be strongest near that component--tapping on or near the amp causes a much louder response than tapping elsewhere on the radio.

I looked at all the solder joints, both my own and the ones the board came with, and I couldn't find any that looked suspect. 

Thanks for the assist!

Tim


Evan Hand
 

Tim,

2 things:
1 - did the rig ever work?  It is always best to get the stock rig to work before you do any modifications.  Since you have already installed the KD8CEC software and it is working do not go back.
2 - Get the Memory Manager software from GitHub:  https://github.com/phdlee/ubitx/releases/tag/v1.11 then use it to see where the calibrations are at this point.  If you go to the HamsKey.com blog, you should be able to find instructions on how to use the Memory Manager.

Once you have the software up and running, connect it to the ubitx and read the current calibration values in the rig.  The calibration value is not so important at this time.  The BFO value is.  It should be somewhere around 11.0550 MHz.  If it is very far from this value (more than 20kHz, then set it to 11.055500 as a starting point and see if the antenna connection changes the received sound.

The microphonic connection could be a cold solder joint on the volume control, a bad volume control (not real likely), a cold solder joint on the board, or the LM386 socket.  There have been some reports in the past about cold solder joints on the crystal filters of the board.  It the soldering that you did passes inspection, then you could take a good magnifying lens or loupe and verify them.  I would suggest you try to isolate the offending part by tapping lightly around the rig to see where the sound is the loudest.

As background, I had this issue with a v4 that I built.  It is still there, as far as I know, just overwhelmed by the signal from the RF sections.  As Reed suggested, the place to start is to ensure that the BFO is calibrated.  Until then, hold off on any major surgery.

Let us know how things progress.
73
Evan
AC9TU


Reed N
 

Hey Tim,

Did you calibrate the oscillator and BFO? That's step number 1 if you haven't already. See Ashhar's video here: https://www.youtube.com/watch?v=t6LGXhS4_O8


Reed


Tim Helming <wt1im@...>
 

Hello hive mind

I just completed a v5 board. I put Ian's (KD8CEC) v1.2 firmware on and set it up with a Nextion 2.4. 

The rig powers up and the GUI behaves like it's supposed to. I get audio--but not the audio I'm expecting. What I'm getting is the rig itself is acting like a microphone. As in, if I tap on the case, I hear the taps through the headphones. I get absolutely no RF receive. Plugging/unplugging the antenna makes no difference, and the rig can't hear CW coming from my own station at all. I don't even really hear static per se, just seemingly the static of the audio circuit itself. Checked BFO, it's right where Ian recommends it to be.

I have very little in the way of test equipment, so it's possible that I'm going to be out of luck without some. I have a basic analog multimeter and that's about it. 

No obvious loose connections or anything like that that I can see. I plugged in a CW key and I can TX on CW, so the TX/RX relay seems to work fine. 

I couldn't find any threads on the forum that referred to this behavior.

Thanks and 73,

Tim

--
Tim Helming, WT1IM
Vice President, Puget Sound Repeater Group